Chlamydiaceae two genera, Chlamydia and Chlamydophilatwo genera, Chlamydia and Chlamydophila small...

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Chlamydiaceae Chlamydiaceae two genera, two genera, Chlamydia Chlamydia and and Chlamydophila Chlamydophila small enough to pass through 0.45-μm small enough to pass through 0.45-μm filters filters obligate intracellular parasites obligate intracellular parasites possess inner and outer membranes similar possess inner and outer membranes similar to those of gram-negative bacteria to those of gram-negative bacteria contain both DNA and RNA contain both DNA and RNA possess prokaryotic ribosomes possess prokaryotic ribosomes synthesize their own proteins, nucleic synthesize their own proteins, nucleic acids, and lipids acids, and lipids susceptible to antibiotics. susceptible to antibiotics.

Transcript of Chlamydiaceae two genera, Chlamydia and Chlamydophilatwo genera, Chlamydia and Chlamydophila small...

ChlamydiaceaeChlamydiaceae

•two genera, two genera, ChlamydiaChlamydia and and ChlamydophilaChlamydophila •small enough to pass through 0.45-μm small enough to pass through 0.45-μm filters filters •obligate intracellular parasites obligate intracellular parasites •possess inner and outer membranes similar possess inner and outer membranes similar to those of gram-negative bacteria to those of gram-negative bacteria•contain both DNA and RNAcontain both DNA and RNA•possess prokaryotic ribosomespossess prokaryotic ribosomes•synthesize their own proteins, nucleic synthesize their own proteins, nucleic acids, and lipidsacids, and lipids•susceptible to antibiotics. susceptible to antibiotics.

ChlamydiaceaeChlamydiaceae

• metabolically inactive infectious forms (elementary bodies [EBs])

• metabolically active, noninfectious forms (reticulate bodies [RBs])

• EBs are resistant to many harsh environmental factors

Table 39-2. Comparison of chlamydial elementary bodies and reticulate bodies

Characteristic Elementary body Reticulate body

Size 0.2-0.3 μm 1 μm

Morphology Electron-dense core, rigid

Fragile, pleomorphic

Infectivity to host Infectious Non-infectious

RNA: DNA ratio 1:1 (condensed DNA core)

3:1 (increased ribosomes)

Metabolic activity Relatively inactive Active, replicating stage

Trypsin digestion Resistant Sensitive

ChlamydiaceaeChlamydiaceae

•The growth cycle of Chlamydia trachomatis

• Electron micrograph of a thin section of chlamydial inclusion showing small elementary body (single arrow) and reticulate body (double arrows)

Chlamydia trachomatisChlamydia trachomatis

• three biovars, trachoma, LGV (lymphogranuloma venereum), and mouse pneumonitis

• serovars-major outer membrane protein • A, B, Ba, C Primarily conjunctiva• D-K Primarily urogenital tract• L1, L2, L2a, L3 Inguinal lymph nodes

Chlamydia trachomatisChlamydia trachomatis

• Most common sexually transmitted bacteria in United States

• Ocular trachoma worldwide (most common in Middle East, North Africa, India

• LGV highly prevalent in Africa, Asia, and South America

Site of infection Disease Organism (serovars)

Eye Trachoma C. trachomatis (A, B, Ba, C)

  Inclusion conjunctivitis C. trachomatis (D-K)

  Ophthalmia neonatorum C. trachomatis (D-K)

  Contact lens-associated Parachlamydia spp.

Genital tract

  Male Non-specific urethritis, proctitis, epididymitis C. trachomatis (D-K)

  Female Cervicitis, urethritis, endometritis, salpingitis, PID, perihepatitis, peri-appendicitis, infertility with tubal occlusion

C. trachomatis (D-K)

  Abortion, premature birth C. trachomatis (D-K)a

  Sheep-related abortion Ch. abortus

  Male and female Lymphogranuloma venereum C. trachomatis (L1-L3)

Respiratory tract Neonatal atypical pneumonia C. trachomatis (D-K)

  Pharyngitis, bronchitis, pneumonia Ch. pneumoniae

    Simkania negevensisa

  Pneumonia Ch. abortus

  Psittacosis, ornithosis Ch. psittaci

Chronic diseases Atherosclerosis, coronary disease Ch. pneumoniaea

  Stroke, multiple sclerosis, sarcoidosis, Alzheimer's disease Ch. pneumoniaeb

Trachoma: Chronic, inflammatory granulomatous process of eye surface, leading to corneal ulceration, scarring, pannus formation, and blindness. Active trachoma, characterized by the presence of lymphoid follicles on the conjunctiva and intermittent shedding of chlamydiae, is primarily a disease of children. By contrast, blindness occurs mainly in adults

Adult inclusion conjunctivitis: Acute process with mucopurulent discharge, dermatitis, corneal infiltrates, and corneal vascularization in chronic disease. Most prevalent in sexually active young people, being spreadfrom

genitalia to the eye.

Neonatal conjunctivitisNeonatal conjunctivitis

• Acute process characterized by a mucopurulent discharge. • Develops in infants around 14 days after birth. • The disease presents as a swelling of the eyelids and orbit,

hyperaemia and a purulent infiltration of the conjunctiva. • Acquired from the mother during birth. • If untreated the infection usually resolves, but a substantial

proportion of these infants develop chlamydial pneumonia about 6 weeks after birth

Genital infection Genital infection Infection in menInfection in men

• C. trachomatis serovars D-K are responsible for about 30% of cases of non-specific urethritis in men.

• This is one of the commonest sexually transmitted infections worldwide and repeat infections are common.

• The infection is often asymptomatic, with infected men serving as a reservoir of infection.

• In symptomatic patients, varying amounts of mucopurulent discharge are produced. Occasionally this progresses to epididymitis or prostatitis, especially in those aged less than 35 years.

• It is likely that chronic chlamydial epididymitis may eventually lead to occlusion of the tube and infertility due to azoospermia.

Genital infection Genital infection Infection in Infection in womenwomen

• In symptomatic women, C. trachomatis serovars D-K cause mucopurulent cervicitis and urethritis.

• However, many women harbour the organism asymptomatically in their cervix.

• Not only a risk to their sexual partners or offspring, but also to themselves, as ascending infection frequently occurs.

• This results first in an endometritis, in which chlamydiae survive monthly menstrual shedding of the uterine lining, followed by infection of the fallopian tubes to cause acute salpingitis.

• Collectively, endometritis and salpingitis are known as pelvic inflammatory disease, which, in most developed countries, is largely caused by C. trachomatis.

• Chlamydial pelvic infection may lead to further abdominal involvement and the formation of pelvic adhesions. Perihepatitis (Fitz-Hugh-Curtis syndrome) and even peri-appendicitis may result.

Lymphogranuloma venereum Lymphogranuloma venereum • Genital tract infection with C. trachomatis

serovars L1-L3 may present as lymphogranuloma venereum.

• Commonest in the tropics, this condition is occasionally seen in developed countries.

• It usually begins with a genital ulcer followed by lymphadenopathy of the regional lymph nodes.

• Buboes are seen if infection persist, can spread to the gastrointestinal and genito-urinary tracts, causing strictures and, in rare cases, peno-scrotal elephantiasis.

ChlamydiaceaeChlamydiaceae

• Lymphogranuloma Venereum • 1 to 4 weeks • a primary lesion • inflammation and swelling of the

lymph nodes • buboes

ChlamydiaceaeChlamydiaceae

•Patient with lymphogranuloma venereum causing unilateral vulvar lymphedema and inguinal buboes

ChlamydiaceaeChlamydiaceae

• Reiter’s syndrome (urethritis, conjunctivitis, polyarthritis and mucocutaneus lesions)

LABORATORY DIAGNOSISLABORATORY DIAGNOSIS

• Cytology • Culture • Nucleic Acid Probes • PCR, LCR• Serology (MIF)

TREATMENT, PREVENTION, AND CONTROLTREATMENT, PREVENTION, AND CONTROL

• LGV tetracycline for 21 days • Ocular and genital infections in

adults should be treated with one dose of azithromycin or doxycycline for 7 days

• Newborn conjunctivitis and pneumonia should be treated with erythromycin for 10 to 14 days

ChlamydiaceaeChlamydiaceae

• Chlamydophila pneumoniae • Respiratory secretions• No animal reservoir• Human pathogen • Bronchitis, pneumonia, and sinusitis• 50% of people have serologic evidence • A significant cause of acute exacerbations of

asthma • Atypical pneumonias • Alzheimer's disease, multiple sclerosis, stroke and

sarcoidosis, but the evidence is even more slender than for heart disease

Chlamydophila pneumoniaeChlamydophila pneumoniae

• MIF• NAAT• Macrolides (erythromycin ,

azithromycin , clarithromycin ), tetracyclines (tetracycline, doxycycline ), or levofloxacin administered for 10 to 14 days

Chlamydophila psittaciChlamydophila psittaci

• the cause of psittacosis-parrot fever• human infections may be asymptomatic or

mild• exposure to an infected bird may not be

suspected• convalescent serum may not be collected

so that the clinical diagnosis can be confirmed

• antibiotic therapy may blunt the antibody response

Chlamydophila psittaciChlamydophila psittaci

• The incubation period is about 10 days • ranges from an 'influenza-like' syndrome,

with general malaise, fever, anorexia, sore throat, headache and photophobia, to a severe illness with delirium and pneumonia.

• tetracyclines or macrolides • Kuş ticareti yasaklanmalıııııı